iMac 24 PSU LITEON PA-3241-02A1 250W

[twingolover]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

hi ,
after a lot of time i have an update.

before buy a new graphica card , i try to reflow the old one.
Now i have this situation.

Imac starts , i hear chime sound on startup and hard disk appear working (i dont' have thuderbolt display to connect a 2nd display) and fans works also.

but totally black screen i don't see nothing!!!!!

Looking for led i have :

Led 1 , green state
Led 2 , green state
Led 3 , off (green for a while when poweron)
Led 4 , off

Please can you help me to troubleshoot issue?
Can be surely graphic card?

Thanks in advance

[mikelcerveaux]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

Hi, Does anyone have the lieon pa-3241-02A1 schematics? Thx

[twingolover]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

hi ,
after a lot of time i have an update.

before buy a new graphica card , i try to reflow the old one.
Now i have this situation.

Imac starts , i hear chime sound on startup and hard disk appear working (i dont' have thuderbolt display to connect a 2nd display) and fans works also.

but totally black screen i don't see nothing!!!!!

Looking for led i have :

Led 1 , green state
Led 2 , green state
Led 3 , off (green for a while when poweron)
Led 4 , off

Please can you help me to troubleshoot issue?
Can be surely graphic card?

Thanks in advance

if it can be useful , after replacing GPU with another one now imac works good.

[VGoliney]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

iMac 24 PSU LITEON PA-3241-02A1 250W

Hi everyone, got an aluminum 24 imac with a faulty PSU. First LED on the motherboard is on so trickle voltage is OK. When pressing the power button, 3 lights flash and then only one, 2 seconds pass then again 3 flash then back to one. I've tested motherboard with working PSU and all is well so not a motherboard issue. I can hear a clicking sound coming from the PSU each time it tries to power on. Also, when the power cable is connected, I notice one of the fans on the imac twitches. Very ocassionaly the imac will power up a bit but will eventually die again. All capacitors look absolutely fine, no bulges, leakage etc. I've had a look at the back of the PSU and I think I found the culprit. One of the mosfets looks blown. The board is darkish in that area and the solder on the front of the mosfet looks bad and its slightly lifted. I've provided photos, problem mosfet is on upper right. Thoughts? Also, does anyone now the part number for the mosfet I can't really make it out as it's heated so much, the numbers arent really legible? Would like to try soldering a new one. So if anyone know I would greatly appreciate it... Thanks

Hello, I have a same problem in my iMac A1125 with the same syntoms and findings on the PCB (look at the photos). I've already ordered the mosfet but can anybody help me and tell where I must solder the gate pin (left one). I am asking than because the tab where the gate goes was ripped from the PCB (probably this was happend when the mosfet had burnt) and all arround is so burnt that I'm not able to find where it goes.

Thanks a lot

[lukelovett]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

Yep, and I have the same problem too.

Lets see if we can get the 2008 iMac going... Just too good to throw away!

I Would like to hear if any others on the forum was able to revive the iMac.

[maki]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

Hello friends
Can someone confirm the values of 2 green components marked as R012 and R040.
I assume these are resistors, but they show open circuit on my PS.

[Siverian]

Re: iMac 24 PSU LITEON PA-3241-02A1 250W

Hello maki,
These are shunt resistors with a nominal 0.012 0.040 Ohm respectively